deturbulated std cirrus flies against Diana 1

"Herb" wrote:

Am I the only one who is completely underwhelmed by this "exiting"
news that comes well timed after the June article in SSA magazine by
Bill Collum? Is anybody able to explain to me even in basic terms
what the physics behind the claimed effect are? Mr. Collums
explanations are not making any sense, he just throws aerodynamic
terms around and invents new ones such as "slip layer" that nobody
else has ever observed.

Herb,

I'm glad the Soaring article on Sumon Sinha's "deturbulator" technology got
you thinking. I am more engineer than reporter, so I apologize if my
explanations were a little unclear. I promise you that the term "slip layer"
is not a product of my over-active imagination (which can, admittedly, run
wild from time to time; wait until you read about my vision of a mid-21st
century sailplane in a future edition of Soaring), but is a formal concept
inherent in computational fluid dynamics. The "slip effect", for example, is
a recognized phenomenon of pipeline fluid flow and effects processes
utilizing non-Newtonian fluids in the petroleum, chemical, and food
preparation industries. Exactly how and under what conditions this effect
may apply to Newtonian fluids (i.e. "air") interacting with a single
boundary wall (i.e. "a wing") is open to question, and that is what Sumon
and Jim are investigating. Essentially, if they are able to successfully
leverage this effect in aerodynamic applications, it is possible that skin
drag may be reduced or virtually eliminated by forcing the boundary layer to
detach from the wing surface. In such a case, the energy-laden boundary
layer will not be in direct contact with the wing surface, but will instead
"slip" over a layer of static air, preventing the boundary layer from
"dumping" it's energy through micro-scale interactions with the surface over
which it is flowing. Obviously, as I mentioned in my recent article, a great
deal more research is required before any conclusions can be drawn. Only
time (and money) will tell if this phenomenon can be practically applied to
sailplane aerodynamics. I applaud Sumon and Jim for their innovation and
perseverance, and wish them well.

Thank again for your comments.

Bill Collum
"Tango X-Ray"




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On Jun 9, 8:09 pm, Herb wrote:
On Jun 9, 2:59 pm, Jim Hendrix wrote:

For the latest parallel flight of my deturbulated Standard Cirrus vs. a
modern glider, go tohttp://sinhatech.com/SinhaFCSD-Progress-06072008.asp#article.

20 minutes of parallel flying should be enough to make the point.

...

Am I the only one who is completely underwhelmed by this "exiting"
news ...

No, you are not the only one who is underwhelmed by this. I spoke to
an aerodymicist who has a wind tunnel (I don't have permission to say
who, so I won't) who has more than once offered Dr. Sinha his wind
tunnel for formal testing - and even thought the offer had been
accepted once - but the offer hasn't resulted in any testing there. I
was also told the Dr. Sinha got the ear of Boeing management, and
there was collegial discussion among aerodynamicists, but whether
Boeing did any tests was unknown to my informant.

The tests done by Dick Johnson, and a side-by-side flyoff, aren't
science; they're anecdote. Interesting anecdote, though...

When we see some systematic wind-tunnel studies, we will have a better
idea how to define the role of these strips.

A key comment in this discussion, by Mr. Hendrix, with respect to the
science, is
"To be brutally frank, it’s taking a long time to develop this
technology
because neither Sumon nor I are very disciplined in our methods ..."

Good science is really hard to do well, and does require disciplined
methods.

Dan Johnson

danlj wrote:


The tests done by Dick Johnson, -snip- aren't
science; they're anecdote.

I disagree. An important part of science is careful measurement
and quantification of an observed phenomenon. Dick Johnson's
careful, systematic measurements are far more than just anecdote.
Are they the whole story? Of course not. Who said they were?

You say you have knowledge of what is going on behind the scenes
and this causes you to question the practices of the deturbulator
inventor. Fine. But are you also saying that Richard Johnson's
measurement techniques and results, not just on the deturbed
Cirrus, are not carefully done and we should dismiss his work?
If so that is a strong statement and I can't say I agree with it.

--
-Doug

** Posted from http://www.teranews.com **

So the patenting is going on?
I hope that after securring the idea by a patent, Mr Sinha will be
more open to the aerodynamically interested.

I do not want to be harsh, but so far it sounds more like a marketing
issue to me. The mystic and uncertainity is only hurting the impatient
glider pilots, not Mr Sinhas interests.

If there is a phenomenon (and I believe you there is), there should be
no problem in investigating it: Find professors of aerodynamics to
tell their students about it, get some thesis`s about it written.
Encourage pilots to try it on their planes. Have the OSTIV be informed
(next meeting is during the WGC in Lüsse). Invite fly&study groups
like the German Akafliegs to try it hands-on. I hope all this will go
on when Mr Sinhas interestes are securred.

This is not about manpower. It is about deciding between money and
pioneering a new phenomenon.

Jonas,

Your comments are on target. Dr. Sinha has only recently yielded to
pressure for full disclosure. A poignant moment was in 2007 when Dick
Johnson presented his report at the SSA Convention and leaned on Sinha to
let him tell about the leading edge tapes. Now he is now holding back
nothing fundamental to what he is doing.

We just submitted an abstract to the AIAA that tells everything in the
clearest language yet. Esteemed aerodynamicists will criticize it, as
they have in the past, for lack of rigorous methodology and definitive
information about the flow-surface interaction, as well as overall wing
aerodynamics. But my view is that facts are facts. Facts do not have to
be blessed by an eminent scientist to be real. Data speaks for itself to
those who listen. The same goes for the quality of the data. Look at my
data (e.g.,
http://sinhatech.com/SinhaFCSD-Progr...ls.asp#article) and
you will find plenty of evidence that this phenomenon cannot be written
off to convection in the air, etc.

I agree with you, let the academic community do the fundamental work that
Sinha and I are not doing. Much needs to be done, it will take many years
and I expect it will branch out into other related methods. I have every
confidence that this will indeed happen, when the academic community is
convinced that there really is something here. Meanwhile, my aim
continues to be to amass so much data that the sheer weight of it will
become undeniable.

Jim Hendrix


At 14:37 16 June 2008, Jonas Eberle wrote:
So the patenting is going on?
I hope that after securring the idea by a patent, Mr Sinha will be
more open to the aerodynamically interested.

I do not want to be harsh, but so far it sounds more like a marketing
issue to me. The mystic and uncertainity is only hurting the impatient
glider pilots, not Mr Sinhas interests.

If there is a phenomenon (and I believe you there is), there should be
no problem in investigating it: Find professors of aerodynamics to
tell their students about it, get some thesis`s about it written.
Encourage pilots to try it on their planes. Have the OSTIV be informed
(next meeting is during the WGC in L=FCsse). Invite fly&study groups
like the German Akafliegs to try it hands-on. I hope all this will go
on when Mr Sinhas interestes are securred.

This is not about manpower. It is about deciding between money and
pioneering a new phenomenon.